Water abundance in four of the brightest water sources in the southern sky

作     者：Bing-Ru Wang Lei Qian Di Li Zhi-Chen Pan 

作者机构：National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012China Key Laboratory of Radio AstronomyChinese Academy of SciencesNanjing 210008China 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2016年第16卷第3期

页      面：17-32页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：supported by the National Basic Research Program of China(973 program,Nos.2012CB821800 and 2015CB857100) the National Natural Science Foundation of China(No.11373038) the Strategic Priority Research Program“The Emergence of Cosmological Structures”of the Chinese Academy of Sciences(Grant No.XDB09000000) 

主　　题：ISM: abundances    (ISM:) HII regions    ISM: molecules    stars: formation 

摘      要：We estimated the ortho-H2O abundances of G267.9–1.1, G268.4–0.9, G333.1–0.4 and G336.5–1.5, four of the brightest ortho-H2O sources in the southern sky observed by the Submillimeter Wave Astronomy Satellite（ortho-H2O1（10） – 1（01） line, 556.936 GHz）. The typical molecular clumps in our sample have H2 column densities of 10^22 to 10^23cm^-2 and ortho-H2O abundances of 10^-10. Compared with previous studies, the ortho-H2O abundances are at a low level, which can be caused by the low temperatures of these clumps. To estimate the ortho-H2O abundances, we used the CS J = 2 → 1 line（97.98095 GHz）and CS J = 5 → 4（244.93556 GHz） line observed by the Swedish-ESO 15 m Submillimeter Telescope（SEST） to calculate the temperatures of the clumps and the 350 μm dust continuum observed by the Caltech Submillimeter Observatory（CSO） telescope to estimate the H2 column densities. The observations of N2H^＋（J = 1 → 0） for these clumps were also acquired by SEST and the corresponding abundances were estimated. The N2H^＋ abundance in each clump shows a common decreasing trend toward the center and a typical abundance range from 10^-11 to 10^-9.